pub struct EntityTag {
    pub weak: bool,
    /* private fields */
}
Expand description

An entity tag, defined in RFC7232

An entity tag consists of a string enclosed by two literal double quotes. Preceding the first double quote is an optional weakness indicator, which always looks like W/. Examples for valid tags are "xyzzy" and W/"xyzzy".

ABNF

entity-tag = [ weak ] opaque-tag
weak       = %x57.2F ; "W/", case-sensitive
opaque-tag = DQUOTE *etagc DQUOTE
etagc      = %x21 / %x23-7E / obs-text
           ; VCHAR except double quotes, plus obs-text

Comparison

To check if two entity tags are equivalent in an application always use the strong_eq or weak_eq methods based on the context of the Tag. Only use == to check if two tags are identical.

The example below shows the results for a set of entity-tag pairs and both the weak and strong comparison function results:

ETag 1ETag 2Strong ComparisonWeak Comparison
W/"1"W/"1"no matchmatch
W/"1"W/"2"no matchno match
W/"1""1"no matchmatch
"1""1"matchmatch

Fields§

§weak: bool

Weakness indicator for the tag

Implementations§

Constructs a new EntityTag.

Panics

If the tag contains invalid characters.

Constructs a new weak EntityTag.

Panics

If the tag contains invalid characters.

Constructs a new strong EntityTag.

Panics

If the tag contains invalid characters.

Get the tag.

Set the tag.

Panics

If the tag contains invalid characters.

For strong comparison two entity-tags are equivalent if both are not weak and their opaque-tags match character-by-character.

For weak comparison two entity-tags are equivalent if their opaque-tags match character-by-character, regardless of either or both being tagged as “weak”.

The inverse of EntityTag.strong_eq().

The inverse of EntityTag.weak_eq().

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Formats the value using the given formatter. Read more
The associated error which can be returned from parsing.
Parses a string s to return a value of this type. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Compare self to key and return true if they are equal.

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Converts self into a collection.
Should always be Self
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
Get the TypeId of this object.